The Presta valve has an inner human body, a valve cap, and an outer stem. What's more, it includes a lock nut which uses to safe the stem into the wheel rim. The air pumping means of this valve is a little bit complicated due to the little valve diameter. https://bookmarkeasier.com/story19591124/how-much-you-need-to-expect-you-ll-pay-for-a-good-presta-addons